The formula H2O is also the molecular formula of water. For non-molecular substances such as table salt, we represent the composition with an empirical formula. Sodium chloride is represented by NaCl, meaning that sodium and chlorine ratio in sodium chloride is 1 to 1. Again, the subscript 1 is omitted.
By Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.Segmentation is also called metamerism.y Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.
Segmented worms (Annelida) are a group of invertebrates that includes about 12,000 species of earthworms, ragworms and leeches. Segmented worms live in marine habitats such as the intertidal zone and near hydrothermal vents.egmented worms are classified within the following taxonomic hierarchy: Animals Invertebrates. Segmented worms are divided into the following taxonomic groups: 1  Polychates-The polychaetes include about 12,000 species that are characterized by having multiple hairs on each segment.